mdetect's output missing

[Ralf Mardorf]

$ man mdetect
[snip]
mdetect writes the autodetected mouse device and protocol to standard
output.  Unless either of the -o or -x options is given, mde‐
tect produces output appropriate for configuring the gpm(1) program.
Alternatively, output appropriate for  an  XFree86  X  server
configuration file is produced.  If the -v option is given, some
information about the program's status is also written to standard
output, but this is largely unimplemented at this writing.
[snip]

If I run it verbose I only get
"[snip]
Found the following devices:
   /dev/ttyS0"

There's no output for X or gpm. Where should I expect standard output?

-- Ralf